Will Front License Plate Hurt Aerodynamics?

it should have some impact on the aerodynamics, the Prius really looks much better w/o it.

Unfortunately here in CA it is required, I asked my sales not to drill into my front bumper but I guess that's the first thing they do when they prep the car after it arrived at the dealership.

some dealers, however have you sign a waiver here in CA if you choose not to have the front plate mounted, usually on higher end cars.

 

I fortunately now live in a state that doesn't require it. We don't even get a second plate unless we order personalized plates. I personally think other states should make it optional as I really don't see the need for the second one. Then again I'm ignorant on this matter so perhaps someone else may be able to point out a reasonable need. After all I believe the plate is to allow an officer to run it before pulling you over. he's not going to run a plate while staring in his rear view mirror. If he did, the state would stamp the front plate in reverse so it would show up right in a mirror. All toll booth cameras and photo radar I've seen snap you from behind.

All I see the plate doing is possibly reducing fuel economy. Perhaps this isn't as bad over sees with the thinner/longer plates but in the US the height of our plates doesn't blend in with the curvature of the bumper.

Mike

 

Getting cited once for lack of the front plate would cost you more than a lifetime of buying the extra gas needed to compensate for the presence of that plate.

 

In response to the aerodynamics question, I don't think the front plate will have much of an effect. The plate is located in the separation zone where the air "decides" to go over or under the car....consequently the air speed there is relatively low, and the plate should have little effect.

 

If it does, I don't notice it. I'm also in Ohio and currently I'm getting around 60 MPG on this tank. More are in the tires and good driving technique will save you much more than removing the plate ever could.


David

 

I'm sorry, but personally I don't think it should matter if it does affect mpgs....if it's the law...follow it. And from a law enforcement standpoint, the front license plate is a nice thing. If there is a suspicious vehicle behind you, you can still run the tag. Also, there is 2x as much of a chance someone will get the plate number when a crime is committed.

 

Having a front plate is important for several reasons, as far as the law is concerned. One, as previously mentioned, if a car is following a patrol car, the plate can be viewed and the car can be identified. Second, if an officer sees a car in a parking lot and the front is facing the isle, the the officer does not have to get out of the car and walk over to the back of the car to see the plate. Third, if a car is driving toward an officer, they can read the plate. Another reason could be someone phoning the police to report something, perhaps a hit and run, reckless driving, etc.... They don't necessarily always only see the back side of the car to see the plate. Heck, it's often enough as is that a vague description of a car is given, much less a make, model, or plate #. These are more or less situations in which viewing the front plate would be a significant advantage.

The reasons for needing such efficiency are many more. Such as what? What if someone stole your car. Do you expect an officer to get out in every parking lot and walk to the backside of every prius (or whatever car should get stolen) to view the back plate? If the thief is still in the car, do you think they will give the officer time to walk around the car? What if a child was abducted and amber alert issued? What if an officer sees a car coming towards him but it doesn't have a front plate? He may not have enough time to turn around (median divider, other traffic, etc...), catch up to the car, and read the plate. Also, when a patrol car rides up being someone that happens to be doing something wrong, and they know it and like to live on the edge, it can invoke a high speed chase. Having a patrol car drive passed you in the opposite direction would probably NOT be as likely to invoke a chase.

The law is the law. Either way, I don't see how a license plate is going to affect mpg. Having a front plate is the law here, so it is moot to me either way. If someone runs without a front plate but is required to have one, and they get pulled over, please make sure to ask the officer why a plate is needed (and report back to PC). While some laws can be questionable, I feel this one is legit. Sorry.

 

Hi All,

A nice smooth bumper is going to have less air drag than with a plate wart on it.

But, if you need the plate on front legally, just move it. Either flat mount it off to the side , or as I have done, J-hook it to the lower grill work. Down on the grill it does double duty as a grill block!

Carefull about that grill blocking, in the desert, or climbing mountains in thin air, or both. Something your probably not going to be doing in Ohio I would think Aaron.

 

I can certainly see the points now of having both plates. I'd be curious if there's some law enforcement on here that can comment on how often the front plate is helpful. I'm not arguing your points but there's 21 states that only require 1 plate and 29 states that require both. If this was a huge problem I'd suspect more states would require both. I think having a law that requires you to affix 2' long vinyl stickers to the top of the roof of your car so your car can be identified by police aircraft would also help identify vehicles in the case of an Amber alert.... but there's a point where the effectiveness is so moot that it's not worth the bother. After all, in theory a state could cut the cost of license plates by 50% if they only printed one. The vinyl sticker ideal is of course is a bit ridiculous of an example but was merely a weak attempt at illustrating that anything can be done if there's a problem that needs to be solved (in this case the identifying of vehicles from the front)... but ultimately what's the return on investment? How many crimes could not have been solved due to a lack of front plate? Initially I would say that any expense that would help recover a child or put a murderer behind bars should be considered, but that brings me back to my vinyl sticker point.... where does one draw the line?

Mike

 

I live in Florida and we have a one plate system. Here if a cop wants your plate number he looks on the back. No biggie. Ever wonder why some states go for two plates and not four or more? Maybe one on the top so a chopper can spy on you too?

:glare:

 

The aerodynamic disruption in air flow probably won't affect your mileage until you go over 150 knots....

Keith

P.S. If you are going that fast, you have other more important issues to deal with.

 

maybe 0.2%~ change aerodynamics. If the law say's you need it, i wouldnt risk it. You can however leave the plate on the dashboard and still be in accordance with the law. Luckily here in las vegas it's not mandatory for a front plate

 

Well, it is really going to depend to a large degree on your Plate number and to a lesser degree on your state name.

Closed numbers and letters that form a Dish type shape such as 0, 4, 6, 8, 9, A, B, D, O, P, Q, and R will trap air flow and reduce your MPG tremendously.

Open numbers and letters provide a channel for air to excape from each letter so they will have much less effect on MPG, such as 1, 2, 3, 5, 7, C, E, FR, G, H, I, J, K, L, M, N, S, T, U, V, W, X, Y, Z.

Fortunately, there are more Open numbers and letters than closed ones. But with gas prices being what they are, the closed characters can be a real delema.

The letter G can be good, because it creates a whilewind effect that acts like a propeller, fulling your car forward.

Here is an actual map of airflows from a wind tunnel test I conducted on my own plate. Note that the yellow areas indicated bowl shaped depressions where air gets trapped.

 

I very much doubt you would have any measurable difference in drag, there is a thin layer of air over the car which barely moves in relation to the panels. there is also a cushion of air in front of the vehicle when it is moving so the plate would make as good as no difference.

 

Mingoglia, you are certainly free to feel the way you do and question the law, however the law IS still the law in these states whether you agree with it or not. We could certainly discuss many more laws that are even more obnoxious/silly, etc.... than this one, however, I personally have no desire to debate such things.

And for what it's worth, the information in my previous post does come from a member of law enforcement.

If you would like to perform some research to determine actual statistics whether a front license plate would help, did help, did not help, in the solving of any crimes, accidents, or other issues involving proper identification of a vehicle, feel free to do so. But for now, it seems to be common sense enough for me that a front plate helps make for easier identification of a car, without getting too obnoxious with putting larger or more forms of identification on the car.

 

Oh, and to add to NoMoShocks answer, don't forget to mention that the coriolis effect causes the reverse air flow south of the Equator. Your excellent drawing is for us Northern Hemisphere folks.

 

Police, especially the speed camera division hate that motorbikes don't need a front number plate because they miss out on issuing a fine when a front on photo is taken.

 

The main reason some states don't issue front plates is that it takes half as many plates. They still charge the same, so it makes more money for the state.

Tom